6 
FETCH : 
usual pitted structure. In normal Hevea wood these walls 
range from 4 ^ to 8 pt, in thickness ; in the fragments of the 
decayed wood they may be 2 p», to 4 pt, in thickness, and these 
may be continuous with the remains of the walls of adjacent 
cells which have been reduced to the middle lamella only. 
The débris stains yellow with chlor-zinc -iodine, but gives no 
colouration with phloroglucin and hydrochloric acid, nor with 
aniline chloride. 
The whole of the tissue of the pseudo-sclerotium is filled with 
the hyphæ of the fungus. These hyphæ, when regular, vary 
from about 6 to 8 p>. in diameter. They form a tangled mass 
in the medullary rays and the vessels, but run longitudinally 
along the fibres. If the hyphæ in the fibres are regular, 
several occur crowded in the lumen of a single fibre, and these 
intertwine in a long spiral. But in general the hyphæ in the 
fibres are irregular, swelling out to a diameter of 12 pi. or so, in 
lengths up to 50 pi. long, or producing a succession of irregular 
inflations. Frequently a hyphæ swells out into a globular 
mass which completely blocks the cells. The walls of these 
hyphæ are strongly thickened (except at the periphery of the 
pseudo-sclerotium), and the lumen in cross section appears 
as a mere point. In their irregular character and thickened 
walls the hyphæ strongly resemble those of a sclerotium. 
In the cells of the periphery of the tissue the h5rphæ are, as a 
rule, thin-walled and collapsed. 
In general shape the various parts of the hyphæ resemble 
those of the sclerotium of Lentinus Woermanni Cohn et 
Schroet. as figured by Bommer (I. PL I., figs. 10-26), or the 
simpler forms from PacJiyma cocos figured by the same author 
(I. PI. IV., figs. 5, 6). They resemble these, too, in being very 
strongly réfringent, but differ in that, in general, it has not 
been possible to observe the existence of a central cavity 
through the tubercular parts of the hyphæ by external 
examination. Cases in which the lumen appears as a darker 
line do occur, but they are not common. 
The hyphæ do not swell in caustic potash ; in that respect 
they differ from the tubercular thickened hyphæ of Pachyma 
cocos as described by Fischer (3). They are not stained by 
chlor-zinc-iodine, nor by iodine in potassium iodide. The 
